The brooch was commissioned by the Royal Regiment of Canadian Artillery, of which the Queen is Captain General — a position she took on when she ascended the throne.
The regiment said the brooch is encrusted with 60 diamonds to mark the Queen's 60th anniversary of her time on the throne.
"This is a gift specifically from her majesty’s Canadian gunner family and symbolizes our gratitude for having this very special relationship between her Majesty and the regiment," said Colonel Commandant Lt.-Gen. Mike Jeffery, who presented the brooch to the Queen at Buckingham Palace.
The position of Captain General is unique to the regiment, but is similar to the Colonel-in-Chief appointment held by other regiments.
A spokeswoman for Montreal-based jeweller Birks, which made the piece, said the Queen was "thrilled to receive such a gift."
"She's always been very close to the regiment over the years, whenever she comes to Canada she makes a point of visiting the regiment," Eva Hartling said in an interview Tuesday. "So the artillery wanted to present her with a very special gift in honour of this 60th anniversary."
The brooch was inspired by the regiment's cap badge, which was designed in 1907. It features a profile view of a "9-pounder" field cannon emblazoned with the regiment's motto and the number 60 over the gun wheel, all placed over a maple leaf made of diamonds, platinum and gold.
A crown on the brooch contains emeralds, rubies and sapphires.
The brooch was a gift paid for by donations from the regiment and Birks, but Hartling said a similar piece would sell commercially for around $15,000 to $20,000.
"It was a great honour for Birks to be working on such a piece," she said. "Hopefully we will see the Queen wearing her brooch really soon."
The brooch isn't the first piece of finery Birks has made for the royals.
"Over the years Birks came to be an official supplier to the royal family," said Hartling adding that the jeweller's Montreal store still has an original royal warrant from the 1930s on hand.
"Birks has been commissioned to create a number of pieces that were gifted by different military groups in Canada to the royal family."
Those pieces include a sterling silver jewel case presented to Queen Elizabeth I from the Black Watch (Royal Highland Regiment) of Canada in 1947 and a silver tray given to Princess Alexandra of Kent from the Queen's Own Rifles of Canada to celebrate her marriage.
Note to readers: This is a corrected story. An earlier version said the Royal Regiment of Canadian Artillery was based in Manitoba and incorrectly identified the Black Watch (Royal Highland Regiment) of Canada.